Cause & solution

You aren't uploading a zip file

we are talking about zip files, so from our download areawe are giving you zipped installers. You have to use that zip file for your default installation. In Safari it is a common issue, that some Safari downloads zip files unzipped and this can cause a confusion. If the zip installation won't work, read the next possible problem.

2

Your server's unzipping program is outdated or it has an error

If you get this error message by using a zip file or by updating the slider, then your server's unzipping program is outdated or it has an error, and it's not able to unzip our zip file. Or it also could be, that during downloading our zip file something bad happened, and your download didn't worked, producing a zip file with an error. To make sure your zip file doesn't have an error, just try to unzip it into your computer. If that works, the server's unzipping should work as well. You should either contact your server host to resolve this error at their end or use the FTP installation/updating method, where you are unzipping the zip file manually, so your server doesn't have to do it: